矿渣基地聚合物固化黄土路用性能试验研究  

Experimental Study on Road Performance of Slag-based Geopolymer Solidified Loess

作　　者：王浩 廖霖[1] 侯泽彪 孔繁盛 崔东霞 WANG Hao;LIAO Lin;HOU Ze-biao;KONG Fan-sheng;CUI Dong-xia(College of Mining Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China;Shanxi Transportation Technology Research and Development Co.,Ltd.,Taiyuan,Shanxi 030031,China)

机构地区：[1]太原理工大学矿业工程学院,山西太原030024 [2]山西省交通科技研发有限公司,山西太原030031

出　　处：《公路交通科技》2024年第10期103-111,138,共10页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51604183);山西省青年科技研究基金项目(201703D111027)。

摘　　要：为解决黄土路基工程建设中大量消耗水泥及砂石骨料的环境资源压力等问题,采用电石渣、脱硫石膏和矿渣多源固废作为主要胶凝成分制备地聚合物加固黄土。系统性开展无侧限抗压强度、劈裂强度、加州承载比、干缩、温缩、冻融循环和扫描电镜等一系列路用性能的室内试验。从固化剂类型、掺量和初始含水率等多个角度探究了固化黄土应用于道路材料的有效性和可行性。结果表明:初始含水率15%、固化剂掺量10%的不同配比固化黄土的7 d无侧限抗压强度均可以满足低等级公路基层和底基层的强度要求;不同配比固化黄土的劈裂强度、加州承载比与抗压强度的变化规律基本一致;掺入适宜配比的地聚合物能减小土体的温缩变形且改善基体自身化学收缩以延缓土体的干缩开裂;经历10次冻融循环后,强度变化指标均在60%以上,抗冻性良好;地质聚合反应生成的大量水化硅酸钙、钙矾石等水化产物具有化学胶结和骨架构建的双重效应,不仅是土体强度形成的主要原因,也阻止了冻融循环对土体微观结构的持续损伤,使孔隙与微裂隙发育受阻,这也是固化土体在复杂气候环境下能长期稳定服役的原因。To solve the environmental resource pressure of consuming large amount of cement and sand-gravel aggregates in the loess subgrade engineering construction,the multi-source solid wastes(e.g.,carbide slag,desulfurization gypsum,and slag)were used as the main cementitious components to prepare geopolymer solidified loess.A series of road performance laboratory tests were carried out,i.e.,unconfined compressive strength,splitting strength,California bearing ratio,dry shrinkage,temperature shrinkage,freeze-thaw cycles,and scanning electron microscopy.The effectiveness and feasibility of solidified loess applying to road materials were explored from multiple perspectives,e.g.,curing agent type,dosage,and initial moisture content.The result indicates that the 7-day unconfined compressive strength of solidified loess with different ratios with 15%initial moisture content and 10%curing agent content can meet the strength requirements of low-grade highway base and subbase.The variations on splitting strength,California bearing ratio and compressive strength of solidified loess with different ratios are basically consistent.Adding appropriate proportion of geopolymer can reduce the soil thermal shrinkage deformation,and improve the chemical shrinkage of matrix itself to delay the soil drying shrinkage cracking.After 10 cycles of freeze-thaw,the strength variation index all above 60%,indicating the good frost resistance.The large amount of hydration products generated by geological polymerization reactions(e.g.,hydrated calcium silicate and ettringite)has dual effect of chemical bonding and skeleton construction.It is not only the main reason why the soil strength forms,but also prevents the continuous damage of freeze-thaw cycles to the soil microstructure,hindering the development of pores and microcracks.It is also the reason why the solidified soil can serve stably for a long time in complex climatic environments.

关 键 词：道路工程 路用材料 室内试验 工业固废 微观机理 

分 类 号：U416.1[交通运输工程—道路与铁道工程]